Merge release-3.10 into master (#6654)

* PLT-6787 Fixed being able to send a post before files finished uploading (#6617)

* Fix quick switcher for channels/users not stored locally (#6610)

* Fix button text on confirm mention modal (#6609)

* fix post delete permission of channel admin (#6608)

* open comment thread for the most recent reply-able message (#6605)

* Use mutex flag with yarn to prevent concurrent builds interfering (#6619)

* Use mutex flag with yarn to prevent concurrent builds interfering

* Remove yarn mutex file with clean

* Minor bug fixes (#6615)

* PLT-6774 - Fixing color for offline icon

* PLT-6784 - Fixing status icon

* Fixing icon margin

* Updating caret position

* PLT-6070 Have ChannelMentionProvider stop searching after a term returns no results (#6620)

* Fixing JS error (#6623)

* Minor bug fixes (#6622)

* PLT-6808 - Updating channel switcher on mobile

* PLT-6743 - Updating scrollbar styling

* Login instead of failing if user exists in OAuth sign-up flow (#6627)

* PLT-6802 Disable team switcher (#6626)

* Disable team switcher

* Fix ESLint errors

* PLT-6807 Ensured select teams page can scroll on iOS (#6630)

* Do not redirect from account switch pages on 401 (#6631)

* Fixing loadtest command and renaming to /test (#6624)

* PLT-6820 Update mattermost-redux dependency (#6632)

* translations PR 20170612 (#6629)

* Bump HTTP client timeout to 30 seconds (#6633)

* For team unreads return empty array instead of null (#6636)

* PLT-6831 Fix status modal localization IDs (#6637)

* Fix status modal localization IDs

* Update test snapshot

webapp/Makefile

@@ -5,7 +5,7 @@ BUILD_SERVER_DIR = ..
 check-style: .yarninstall
 	@echo Checking for style guide compliance
 
-	yarn run check
+	yarn run check --mutex file:/tmp/.yarn-mutex
 
 test: .yarninstall
 	cd $(BUILD_SERVER_DIR) && $(MAKE) internal-test-web-client
@@ -13,7 +13,7 @@ test: .yarninstall
 .yarninstall: package.json
 	@echo Getting dependencies using yarn
 
-	yarn install --pure-lockfile
+	yarn install --pure-lockfile --mutex file:/tmp/.yarn-mutex
 
 	touch $@
 
@@ -22,7 +22,7 @@ build: .yarninstall
 
 	rm -rf dist
 
-	yarn run build
+	yarn run build --mutex file:/tmp/.yarn-mutex
 
 run: .yarninstall
 	@echo Running mattermost Webapp for development
@@ -49,8 +49,9 @@ endif
 clean:
 	@echo Cleaning Webapp
 
+	yarn cache clean --mutex file:/tmp/.yarn-mutex
+
 	rm -rf dist
 	rm -rf node_modules
 	rm -f .yarninstall
-
-	yarn cache clean
+	rm -f /tmp/.yarn-mutex